DNA nucleases (DNases) are ubiquitous in biological cells and are involved in a number of cellular functions including, for example, DNA replication and repair. Certain microorganisms (e.g., Branhamella catarrhalis, Staphylococcus aureus, Serratia marcescens, Streptococcus pyogenes, Bacillus subtilis, Vibrio alginolyticus, Cryptococcus neoformans, Fusarium solani) produce DNases that are excreted out of the cells.
DNA nucleases (DNases) are used in a variety of research and diagnostic applications. DNase activity assays have been developed to monitor the enzyme. In research applications, DNase assays frequently employ radiolabeled DNA substrates and require separation of the products of the reaction from the unreacted substrate before quantification of enzyme activity. Tolun and Myers developed a continuous DNase assay based on the differential fluorescence output of a DNA dye ligand (Nuc. Acid Res. 31:e111, 2003). Their assay requires a spectrofluorometer to detect the DNase activity.
DNA nucleases have been used to detect microorganisms, such as Staphylococcus aureus, which excrete the enzyme into the environment surrounding the cells or colonies of cells. Culture media comprising nutrients, agar, and an indicator system comprising DNA (typically, high molecular weight DNA or large oligonucleotides) and either 100 μg/mL toluidine blue 0 or 50 μg/mL methyl green have been used in methods to detect S. aureus. The culture methods typically require laborious procedures to prepare the agar which, once prepared, must be used within a relatively short period of time.
There exists a need for stable articles and simple, inexpensive methods to detect DNase activity and to detect microorganisms that produce DNase enzymes.